下腔静脉先天畸形MSCT表现及临床意义

目的 探讨下腔静脉(IVC)先天畸形的MSCT表现及其临床意义。方法 回顾性分析960例患者中48例IVC先天畸形的腹部增强CT影像资料,观察MSCT动脉期和静脉期IVC后处理图像及其属支的解剖结构。结果 IVC先天畸形的发生率为5.00%(48/960)。左IVC 4例(4/48,8.33%),CT示肾下段IVC位于腹主动脉左侧;双IVC 5例(5/48,10.42%),CT示腹主动脉两侧上行的IVC;主动脉后型左肾静脉12例(12/48,25.00%),CT示左肾静脉走行于腹主动脉后方;环主动脉型左肾静脉26例(26/48,54.17%),CT示左肾静脉分两支环绕腹主动脉,在不同水平分别注入IVC;IVC伴奇静脉延续畸形1例(1/48,2.08%),增强CT示IVC向上延续为奇静脉,肝静脉直接回流至右心房。结论 MSCT可清晰、直观地显示IVC畸形,对诊断与IVC有关的疾病和防止术中血管损伤有重要临床意义。     

320排螺旋CT直接法下腔静脉成像

目的探讨320排螺旋CT直接法下腔静脉CT血管造影(CTP)的可行性及临床应用价值。方法采用Aq-uilion One 320排螺旋CT对13例疑诊为下腔静脉阻塞的患者行直接法下腔静脉CTP检查,通过Vitrea 4.0后处理工作站对原始图像进行VR、MIP及MPR重建。由1名医师测量左肾静脉汇入下腔静脉处上方1 cm处的CT值,另2名医师采用9段分段法对下腔静脉及其属支的图像质量进行评价。结果对13例患者均顺利完成下腔静脉CTP检查;CT值为(341.33±62.95)HU;13例共117个血管节段中,图像质量为优、良、中等、差的节段分别为64、29、16、8个。重建图像可直观显示下腔静脉的结构、病变部位、范围及狭窄程度。结论直接法下腔静脉CTP用以诊断下腔静脉阻塞性病变切实可行,且具有较高的临床应用价值。     

New Noninvasive Assessment of Liver Fibrosis in Chronic Hepatitis B

Objective. A novel parameter acquired from conventional B‐mode sonographic videos was introduced in this study, and its diagnostic accuracy for evaluation of hepatic fibrosis was investigated. Methods. Twenty‐eight patients with chronic hepatitis B and 8 patients with hepatic cysts in the right lobe (controls) were enrolled. B‐mode sonographic videos of hepatic motion under the ensisternum in the sagittal plane were captured during peaceful breathing. Maximal accumulative respiration strain (MARS) values of hepatic tissue were obtained after image analysis. METAVIR scoring after liver biopsy was considered the standard. First, the relationship between MARS and the fibrotic stage was studied; and second, receiver operating characteristic (ROC) curves were used to assess the accuracy of MARS for evaluation of the fibrotic stage. Results. When the transducer was placed in the sagittal imaging plane under the ensisternum during the whole respiratory period, the hepatic tissue motion was almost in the same plane. The MARS values (mean ± SD) were 29.44% ± 10.44% in the F0 group (no fibrosis; n = 8), 19.30% ± 9.10% in the F1 group (portal fibrosis without septa; n = 8), 18.09% ± 7.36% in the F2–F3 group (portal fibrosis with few septa or numerous septa without cirrhosis; n = 12), and 14.16% ± 4.18% in the F4 group (cirrhosis; n = 8). The Spearman correlation coefficient between MARS and the fibrotic stage was 0.516 (P = .001). The diagnostic accuracy rates, expressed as areas under the ROC curves, were 0.87 for mild fibrosis (F ≥ 1), 0.72 for substantial fibrosis (F ≥ 2), and 0.75 for cirrhosis (F = 4). Conclusions. Maximal accumulative respiration strain attained from B‐mode sonographic videos of hepatic tissue is a new, convenient, economical, and promising noninvasive parameter for assessment of hepatic fibrosis in patients with chronic hepatitis B.     

Liver hemodynamic flow balance by image-directed Doppler ultrasound evaluation in normal subjects.

Image-directed Doppler ultrasonography of main hepatic vessels (hepatic artery, portal vein, hepatic veins, and inferior vena cava (IVC)] was performed in 22 healthy volunteers, 20 years to 65 years of age. For each vessel an estimate was made of the diameter, velocity time interval (VTI), volume blood flow in relation to heart rate (stroke volume in L/min/beat), and body size (blood flow index in L/min/m2 body surface area). Moreover, a hemodynamic hepatic balance to define a range of values in normal population was described. The summation of flow of hepatic veins and IVC flow, just over renal veins, (= IVC subhepatic flow) was significantly correlated with the IVC flow rate before entrance into the atrium (R2 = 0.90). Hepatic artery flux plus portal vein flux plus subhepatic vein flux was also related to IVC flux before right atrium entrance (R2 = 0.92). This study confirms the utility and efficiency of Doppler ultrasonography in understanding liver flow hemodynamic balance.     

64层螺旋CT血管成像技术对Budd-Chiari综合征侧支循环的评价

目的：探讨64层螺旋CT血管成像（CTA）技术对Budd-Chiari综合征（BCS）侧支循环的显示价值。方法：对74例BCS病人术前行CTA检查,观察肝静脉、下腔静脉病变类型及侧支循环情况。结果：74例均诊断为混合型BCS,下腔静脉和肝静脉存在不同程度的梗阻,每一例病人均有侧支循环形成。侧支循环分为肝内侧支、肝外侧支及门静脉-体静脉交通。肝内侧支循环分为6种类型：①肝静脉-副肝静脉引流型（n=47,63.5%）;②肝静脉-肝静脉引流型（n=5,6.7%）;③肝静脉-副肝静脉加肝静脉引流型（n=6,8.1%）;④腔-肝-房引流型（n=4,5.4%）;⑤肝静脉-脐静脉引流型（n=4,5.4%）;⑥肝静脉-肝被膜下静脉引流型（n=8,10.8%）。上述6型肝内侧支均通过数量不等、内径不同的交通支经引流静脉引流入肝段下腔静脉、右心房、脐静脉或被膜下肝静脉与体循环相通。肝外侧支循环分为4种类型：①腰静脉-腰升静脉-奇静脉及半奇静脉侧支型（n=74,100%）;②左肾静脉-腰升静脉-半奇静脉侧支（n=74,100%）和左肾静脉-左膈下静脉侧支型（n=48,64.8%）;③肾静脉-肾包膜下静脉-腹壁浅静脉侧支型（n=26,35.1%）;④腹壁浅静脉侧支型（n=10,13.5%）。结论：64层螺旋CTA可无创性清晰显示BCS患者各种类型的侧支循环途径,对指导临床选择正确的治疗方案具有重要价值。     

Subcutaneous Buffered Lidocaine for Intravenous Cannulation: Is There a Role in Emergency Medicine?

Abstract. Objective: To prospectively evaluate whether subcutaneous buffered lidocaine (SQBL) significantly reduces the pain or adversely affects the success rate of IV cannulation (IVC) in adult ED patients. Methods: A convenience sample of patients a 18 years old requiring IVC in a regional military ED were prospectively randomized to receive SQBL, SQ normal saline with 0.9% benzyl alcohol (SQNS), or no pretreatment (NPTx), prior to IVC with an 18-gauge angiocatheter. SQ infiltration was accomplished using a 27-gauge insulin syringe. Investigators and patients were blinded to SQBL and SQNS in the pretreatment groups. The number of attempts at IVC was recorded for each patient. A 100-mm visual analog pain scale (VAPS) was used to record pain scores for both SQ infiltration and IVC. Comparisons of the mean numbers of attempts to achieve IVC and of the VAPS scores were accomplished by analysis of variance followed by Duncan's multiple range test if significance was found. Results: A total of 103 patients (SQBL-34, SQNS-30, and NPTx-39) were enrolled between November 15, 1996, and June 13, 1997. There were no significant differences among the groups in either the mean number of attempts (SQBL = 1.35, 95% CI ± 0.260; SQNS = 1.13, 95% CI ± 0.124; and NPTx = 1.28, 95% CI ± 0.203) (p = 0.367) or the success rate on the first attempt (SQBL = 79.4%, SQNS = 86.7%, NPTx = 79.5%) (p = 0.533). The median VAPS score of rVC without pretreatment (21 mm, 95% CI ± 7.97) was greater than that for SQBL infiltration alone (10 mm, 95% CI ± 9.11), SQNS infiltration alone (9 mm, 95% CI ± 7.37), and IVC after SQBL (6 mm, 95% CI ± 9.18) (p < 0.009 for each group). SQNS infiltration had no significant effect on the VAPS score of subsequent rVC (20 mm, 95% CI ± 10.5) compared with IVC without pretreatment (21 mm). Conclusions: SQBL significantly reduced the pain, while not adversely affecting the success rate, of IVC in adult patients in the ED.     

多排螺旋计算机断层摄影肾上腺静脉成像

  目的  探讨多排螺旋计算机断层摄影(multi-slice spiral computed tomography, MSCT)静脉成像显示双侧肾上腺静脉的图像质量, 并对肾上腺静脉解剖及变异进行形态学观察。  方法  回顾性分析100例双侧肾上腺形态大致正常的患者腹部增强CT图像, 用最大密度投影(maximum intensity projection, MIP)或多平面重建(multi-planar reconstruction, MPR)显示双侧肾上腺静脉, 评价图像质量, 并分别描述肾上腺静脉解剖位置、变异及与左肾静脉和下腔静脉的关系。  结果  以MIP或MPR技术评价图像质量, 左肾上腺静脉97例(97%)为1级, 1例(1%)为2级, 2例(2%)为3级; 右肾上腺静脉52例(52%)为1级, 19例(19%)为2级, 29(29%)例为3级。左肾上腺静脉均为1支; 91%与膈下静脉汇合后汇入左肾静脉; 左肾上腺静脉平均直径(3.6±0.6)mm(2.4~4.5 mm); 左肾上腺静脉与左肾静脉形成交角, 平均为(121.9±16.0)°(150~58°)。2例发现右侧双支肾上腺静脉; 67例(94%)右肾上腺静脉汇入下腔静脉, 4例(6%)汇入右副肝静脉; 右肾上腺静脉平均直径(3.2±0.5)mm(1.9~4.0 mm); 右肾上腺静脉与下腔静脉形成交角, 平均为(75.3±16.6)°(90~35°)。  结论  多排螺旋CT双侧肾上腺静脉成像结合MIP和MPR技术可清晰显示大部分肾上腺静脉, 尤其是左肾上腺静脉。     

Color flow sonographic mapping of intravascular extension of malignant renal tumors

The purpose of this study was to evaluate the possible role of CDFI in identifying malignant renal tumor thrombus in the renal vein or the IVC. This study involved 24 tumors in 23 patients, including 19 renal cell carcinomas, four Wilms' tumors, and one rhabdoid tumor. CDFI had an overall sensitivity of 95% in predicting combined renal vein and IVC tumor involvement but was more sensitive in the renal vein alone (100%) than in the IVC alone (89%). Specificity of CDFI was nearly equal for both renal vein and IVC thrombus at 85%. The main limitation of CDFI was its inability to predict venous tumor extension in large or bulky tumors. We would recommend CDFI as a method of detecting renal vein or IVC thrombus at the time of initial real-time sonographic detection of tumor. When CT or MR imaging is equivocal, CDFI may be used to predict tumor thrombus in the renal vein or IVC.     

Steato-Score: Non-Invasive Quantitative Assessment of Liver Fat by Ultrasound Imaging

Non-alcoholic fatty liver disease is becoming a global epidemic. The aim of this study was to develop a system for assessing liver fat content based on ultrasound images. Magnetic resonance spectroscopy measurements were obtained in 61 patients and the controlled attenuation parameter in 54. Ultrasound images were acquired for all 115 participants and used to calculate the hepatic/renal ratio, hepatic/portal vein ratio, attenuation rate, diaphragm visualization and portal vein wall visualization. The Steato-score was obtained by combining these five parameters. Magnetic resonance spectroscopy measurements were significantly correlated with hepatic/renal ratio, hepatic/portal vein ratio, attenuation rate, diaphragm visualization and portal vein wall visualization; Steato-score was dependent on hepatic/renal ratio, attenuation rate and diaphragm visualization. Area under the receiver operating characteristic curve was equal to 0.98, with 89% sensitivity and 94% specificity. Controlled attenuation parameter values were significantly correlated with hepatic/renal ratio, attenuation rate, diaphragm visualization and Steato-score; the area under the curve was 0.79. This system could be a valid alternative as a non-invasive, simple and inexpensive assessment of intrahepatic fat.     

Implantable intravascular defibrillator: evaluation of defibrillation waveforms with inferior vena cava electrode system

Background: A percutaneously placed, totally intravascular defibrillator has been developed that shocks via a right ventricular (RV) single‐coil and titanium electrodes in the superior vena cava (SVC) and the inferior vena cava (IVC). This study evaluated the defibrillation threshold (DFT) with this electrode configuration to determine the effect of different biphasic waveform tilts and second‐phase durations as well as the contribution of the IVC electrode. Methods: Eight Bluetick hounds (wt = 30–40 kg) were anesthetized and the RV coil (first‐phase anode) was placed in the RV apex. The intravascular defibrillator (PICD^®, Model no. IIDM‐G, InnerPulse Inc., Research Triangle Park, NC, USA) was positioned such that the titanium electrodes were in the SVC and IVC . Ventricular fibrillation was electrically induced and a Bayesian up‐down technique was employed to determine DFT with two configurations: RV to SVC + IVC and RV to SVC. Three waveform tilts (65%, 50%, and 42%) and two second‐phase durations (equal to the first phase [balanced] and truncated at 3 ms [unbalanced]) were randomly tested. The source capacitance of the defibrillator was 120 μF for all waveforms. Results: DFT with the IVC electrode was significantly lower than without the IVC electrode for all waveforms tested (527 ± 9.3 V [standard error], 14.5 J vs 591 ± 7.4 V, 18.5 J, P < 0.001). Neither waveform tilt nor second‐phase duration significantly changed the DFT. Conclusion: In canines, a totally intravascular implantable defibrillator with electrodes in the RV apex, SVC, and IVC had a DFT similar to that of standard nonthoracotomy lead systems. No significant effect was noted with changes in tilt or with balanced or unbalanced waveforms. (PACE 2011; 34:577–583)     

两种水力流变除栓导管体外除栓效果比较

目的　比较 7FHydrolyser和 8FOasis两种流变血栓清除导管在模拟股静脉的体外流体模型中的除栓效果 ,注入盐水量及回收液体量 ,以及与除栓过程相关的远端栓塞率。方法　用 3天的猪血在模拟股静脉的体外流体模型中形成约 2 0cm长的血栓栓塞 ,分别使用 7FHydrolyser导管和 8FOasis导管进行血栓清除 (每组 10例 )。 结果　平均除栓时间 7FHydrolyser为 ( 30± 8)s ,8FOasis为 ( 48± 16 )s ;平均注入盐水量 7FHydrolyser( 118± 32 )ml,8FOasis为 ( 14 7± 47)ml;平均回收液体量 7FHydrolyser( 15 5± 43)ml ,8FOasis为 ( 2 2 0± 6 9)ml;注入盐水量与回收液体量的比值 7FHydrolyser为 0 .76± 0 .0 5 ,8FOasis为 0 .6 6± 0 .0 2 ;血栓清除率 7FHydrolyser为 ( 96 .2 7± 1.10 ) % ,8FOasis( 97.2 1± 0 .73) % ;除栓后远端微栓子形成率 7FHydrolyser为 ( 3 .5 7± 1.13) % ,8FOasis( 1.94± 0 .70 ) %。 结论　两种流变除栓导管的血栓清除率均较高 ,在清除时间、回收液体量、注入量与回收液体量的比值方面 7FHydrolyser优于 8FOasis ;在远端微栓子形成率方面 8FOasis优于7FHydrolyser。     

彩色多普勒超声心动图诊断新生儿心下型肺静脉异位引流

目的 探讨彩色多普勒超声心动图在心下型肺静脉异位引流诊断中的价值。方法 患者为３例出生６天、７天及２５天的新生儿。采用Ｈｐ Ｓｏｎｏｓ５５００型彩色多普勒超声诊断仪,探头频率１２ＭＨｚ,经胸行二维超声心动图及彩色多普勒血流图检测。结果 心下型肺静脉异位引流的超声心图特征为左房明显小,房水平右向左分流,其后方见肺总静脉、与左房无交通,追踪其瞳向右下穿过膈肌、于肝右叶后方入门静脉或肝静脉。剑下主动脉短     

Variations of the left and middle hepatic veins: Application in living related hepatic transplantation

The anatomic variations of the middle hepatic vein (MHV) and left hepatic vein (LHV) in 200 patients with normal liver function were analyzed using ultrasonography to clarify the feasibility of resecting the left lobe or left lateral segment in living subjects for living related hepatic transplantation (LRHT). The MHV and LHV form a common trunk in 70% of cases but drain independently into the inferior vena cava (IVC) in 30%. In 7% of cases, the left median vein (LMV) drains into the MHV, in 32% of cases the anterior superior segmental vein (ASSV) that drains segment 8 flows into the MHV. The distance between the two confluence points (LHV flows into MHV or IVC and LMV flows into the MHV) ranged from 0.3 cm to 2.5 cm with an average of 0.75 cm. The diameter of the LMV at the point that flows into MHV ranged from 0.3 cm to 0.9 cm. with an average of 0.61 cm. The distance from the IVC to the confluence of the MHV and LHV ranged from 0 cm to 3.5 cm with an average of 1.5 cm in those cases whose MHV and LHV presented as common trunks. Preoperative delineation of this complex venous anatomy is of paramount importance because the hepatic veins have to be transected in the cutting plane of the liver. The location of this plane is determined by the optimal graft volume required, and both the graft and the remnant liver have to retain perfect function. The venous anatomy would change the cutting plane in the living donor and the surgical method of anastomosis for the recipient. © 1996 John Wiley & Sons, Inc.     

Tissue Doppler of Early Mitral Filling Correlates With Simulated Volume Loss in Healthy Subjects

Objectives: The accurate noninvasive assessment of preload in emergency department (ED) patients remains elusive. Point‐of‐care ultrasound (US) imaging, particularly evaluation of the inferior vena cava (IVC), has been shown to be qualitatively helpful. Doppler and tissue Doppler are now routinely available on ED US equipment, but few studies have looked at the correlation of dynamic changes in these parameters in a controlled model of hypovolemia. Our objective was to examine the correlation of Doppler parameters to simulated volume loss in healthy subjects using a lower‐body negative pressure (LBNP) model and to compare these measurements to commonly used IVC measurements of preload. Methods: Twelve paid volunteers with no known cardiovascular disease between the ages of 23 and 31 years old (mean ± SD = 25.5 ± 2.5 years old) were recruited. Hypovolemia was simulated using graduated LBNP levels with measurements taken at 0, ?30, and ?60 mm Hg and lower pressures as tolerated. Vital signs were monitored in all patients. US measurements recorded at each negative pressure level included IVC maximum (IVC_max) and minimum (IVC_min) dimensions; early (E) and late (A) transmitral filling velocities using pulsed‐wave spectral Doppler; and early (E′) and late (A′) tissue Doppler velocities at the septal (_sep) and lateral (_lat) mitral annulus, using pulsed‐wave tissue Doppler. Results: Lower‐body negative pressure correlated significantly and positively within subjects for all US parameters except for the A filling wave. E′_lat and E′_sep showed the strongest correlation with R² values of 0.749 (95% confidence interval [CI] = 0.577 to 0.854) and 0.738 (95% CI = 0.579 to 0.875) respectively, followed by A′_sep 0.674 (95% CI = 0.416 to 0.845), IVC_max 0.638 (95% CI = 0.425 to 0.806), A′_lat 0.547 (95% CI = 0.280 to 0.802), IVC_min 0.512 (95% CI = 0.192 to 0.777), and E 0.478 (95% CI = 0.187 to 0.762). Ratios correlated only moderately with LBNP level, including E/ E′_latR² of 0.430 (95% CI = 0.131 to 0.706), E/ E′_sep 0.416 (95% CI = 0.183 to 0.686), and IVC collapsibility index (IVC_CI) 0.201 (95% CI = 0.003 to 0.681). Vital signs, including heart rate and blood pressure, did not vary significantly with LBNP levels. Conclusions: In this pilot study of healthy subjects, tissue Doppler assessment of early diastolic filling correlated most strongly with simulated hypovolemia. ACADEMIC EMERGENCY MEDICINE 2010; 17:1162–1168 © 2010 by the Society for Academic Emergency Medicine     

Portal Vein Pulsatility Ratio Provides a Measure of Right Heart Function in Chronic Heart Failure

Portal vein flow was recorded by color Doppler sonography in 31 patients with chronic heart failure and 18 control subjects. Compared with patients showing a forward flow (Group A), those with reversed portal vein flow (Group B) had higher prevalence of tricuspid regurgitation (75% vs. 43%), hepatic congestion (100% vs. 30%) and ascites (50% vs. 18%), and showed higher right atrial pressure (25.3 ± 3.01 mmHg vs. 11.8 ± 5.75 mmHg, p < 0.01). In controls, portal vein pulsatility ratio was 0.66 ± 0.08, in Group A it was 0.46 ± 0.28 (p < 0.01), in Group B −0.60 ± 0.19 (p < 0.01). Portal vein pulsatility ratio negatively correlated with right atrial pressure (r = −0.87; p < 0.01). In Group A, hepatic congestion, ascites and tricuspid regurgitation were associated with a higher portal vein pulsatility. This study indicates that portal vein pulsatility ratio reflects the level of impairment of the right heart.     

The effect of supine versus upright patient positioning on inferior vena cava metrics

Background

Ultrasound of the inferior vena cava (IVC) is a noninvasive and rapidly obtainable method of intravascular volume assessment; however not all patients can lie supine for this procedure. In this study we assess whether patient positioning affects IVC diameter metrics.

Methods

This was a prospective convenience sample of patients in an in-patient dialysis unit at an urban tertiary care center. IVC metrics taken in the supine patient, and then at 45o semi-upright position, pre and post dialysis. Measurements were taken in M-mode in longitudinal plane roughly 2 cm below the level of the diaphragm. IVC-maximum and IVC-minimum diameter measurements were used to determine the IVC collapse index (IVC Max − IVC Min)/IVC Max). Statistics such as means, frequencies and percentages, intraclass correlation coefficient and Bland Altman summary statistics were calculated.

Results

Forty-five patients were enrolled. Average age was 57 years, 69% were male, 73% were African American, 82% had hypertension, 42% had diabetes. There was good to excellent agreement between supine and upright IVC measurements. Both the IVC minimum and maximum measurements had similar coefficient correlation (ri) measurements (0.917 and 0.890 respectively), whereas agreement in the collapse index was lower (ri = 0.813). Bland Altman analysis demonstrated excellent agreement and small 95% limits of agreement (± 6 mm) with minimal mean bias for both the minimum and maximum measurements.

Conclusion

IVC metrics do not change significantly based on patient position. For those patients who are unable to lay completely supine, a semi-upright measurement of the IVC for volume status may be an accurate alternative.     

Computational Method to Predict Esophageal Temperature Elevations During Pulmonary Vein Isolation

Background: The esophagus is in close proximity to the posterior wall of the left atrium, which renders it susceptible to thermal injury during radiofrequency (RF) ablation procedures for atrial fibrillation (AF). Real‐time assessment of esophageal position and temperature (T °) during pulmonary vein (PV) isolation has not been extensively explored. Objective: To develop a protocol that allows estimation of the potential for, and avoidance of, esophageal heating. Methods: In consecutive patients who underwent PV isolation, a thermal probe was used to monitor T ° fluctuations in the esophagus during application of RF energy. The tip of the thermal probe was positioned at the level of the targeted PV and RF was discontinued for T ° rise >0.5°C. The proximity of individual PVs to the esophagus was measured from the temperature probe tip to the closest posterior part of the Lasso catheter from review of biplane projections (left anterior oblique 60° and right anterior oblique 30°). These raw distances were entered into the Pythagorean theorem and the actual distance between the esophageal thermal probe and PV antrum was determined. Results: The study cohort included 44 patients (60 ± 11 years, 61% male, 57% lone AF). The thermal probe in the esophagus was closer to the left‐sided PVs (left common pulmonary vein: 20.9 ± 13 mm, left upper pulmonary vein: 20.5 ± 11 mm, left lower pulmonary vein: 23.4 ± 10 mm) than the right‐sided ones (right common pulmonary vein: 31.0 ± 11 mm, right upper pulmonary vein: 41.9 ± 18 mm, right lower pulmonary vein: 34.5 ± 16 mm). A T ° increase >0.5°C occurred during 116/1,495 (7.8%) deliveries. A T ° rise was more likely during ablation of left‐sided PVs than right‐sided PVs (55% vs 10%, P < 0.0001) and when RF was delivered ≤24 mm from the esophagus (sensitivity 91%, specificity 81%, positive predictive value 75%, and negative predictive value 93%). Conclusion: A thermal probe placed in the esophagus provides real‐time T ° monitoring and anatomic localization. A T ° rise is more likely during ablation of left PVs and during RF deliveries within 24 mm of the esophageal thermal probe. (PACE 2010; 33:1239–1248)     

下腔静脉血经肝回流入右心房：布—加氏综合征的一种特殊类型

目的 回顾性研究一种特殊类型的布－加氏综合征：下腔静脉肝回流入右心房。方法 彩多多普勒超声检查１１４例布－加氏综合征患者,观察下腔静脉和三支肝静脉的走行、入口和血流方向以及肝内外交流支。结果 共５例布－加氏综合征患者呈现特殊循环方式,表现为肝段下腔静脉血经一支肝静脉入肝,通过肝内交通支 另一支肝静脉回流右心房。诊断均经介入手术证实。结果 下腔静脉血经肝加 型布－加氏综合征是一种少见类型,其特点是下     

Ultrasound Assessment of Severe Dehydration in Children With Diarrhea and Vomiting

Objectives: The objective of this study was to determine the test characteristics for two different ultrasound (US) measures of severe dehydration in children (aorta to inferior vena cava [IVC] ratio and IVC inspiratory collapse) and one clinical measure of severe dehydration (the World Health Organization [WHO] dehydration scale). Methods: The authors enrolled a prospective cohort of children presenting with diarrhea and/or vomiting to three rural Rwandan hospitals. Children were assessed clinically using the WHO scale and then underwent US of the IVC by a second clinician. All children were weighed on admission and then fluid‐resuscitated according to standard hospital protocols. A percent weight change between admission and discharge of greater than 10% was considered the criterion standard for severe dehydration. Receiver operating characteristic (ROC) curves were created for each of the three tests of severe dehydration compared to the criterion standard. Results: Children ranged in age from 1 month to 10 years; 29% of the children had severe dehydration according to the criterion standard. Of the three different measures of dehydration tested, only US assessment of the aorta/IVC ratio had an area under the ROC curve statistically different from the reference line. At its best cut‐point, the aorta/IVC ratio had a sensitivity of 93% and specificity of 59%, compared with 93% and 35% for IVC inspiratory collapse and 73% and 43% for the WHO scale. Conclusions: Ultrasound of the aorta/IVC ratio can be used to identify severe dehydration in children presenting with acute diarrhea and may be helpful in guiding clinical management. ACADEMIC EMERGENCY MEDICINE 2010; 17:1035–1041 © 2010 by the Society for Academic Emergency Medicine